Abstract
Abstract
Background: Pleuropulmonary blastoma (PPB) is a rare and aggressive pediatric thoracic malignancy within the DICER1 syndrome spectrum. Despite well-established multimodal treatment based on surgery and chemotherapy, evidence guiding the use of adjuvant radiotherapy remains scarce, given the rarity of this tumor. Case report: A 3-year-old girl with type II PPB, presenting with recurrent pyopneumothorax, achieved a 76% tumor reduction after seven cycles of IVADo chemotherapy, allowing incomplete surgical resection with residual viable tumor. Adjuvant VMAT (45 Gy/25 fractions) achieved excellent target coverage with organ sparing and was well tolerated (grade 2 radiodermatitis only), and the patient remained disease-free at 9 months. Conclusion: This case highlights the feasibility of modern VMAT-based adjuvant radiotherapy for incompletely resected type II PPB and illustrates how advanced treatment planning can optimize local control while limiting radiation exposure to critical organs.